Multiple control



March 3, 1931. E. A. BOHLMAN MULTIPLE CONTROL Original Filed May 22,1926 2 Sheets-Sheet 1 a Fuv u TRUE-Z2 an rfi 17150222122527.-

March 3, 1931. E. A. BOHLMAN MULTIPLE CONTROL 1 Original Filed May 22,1926 2 Sheets-Sheet 2 727179 1770f" T" [F1755 1750121 172522. E ,M

Patented Mar. 3, 1931 UNITED STATES PATENT OFFICE ERNEST A. BOHLMAN, OFCHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITCHBOARD AND SUPPLY COMPANY,OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS MULTIPLE CONTROLOriginal application filed Kay 22, 1926, Serial No. 110,899. Divided andthis application filed September This is a divisional application of mycopendin application Serial Number 110,899, filed lay 22, 1926, nowPatent Number 1,710,720. 7

My invention relates to tuning couplers or transformers as are used inwireless telegraph or telephone receiving systems, and resides in anovel method of construction and operation of the same.

A feature of my invention resides in a multiple control arrangement forsuch devices.

Another feature of my invention has to do with the manner in which thecoils are mounted and associated with one another, and the constructionand control of the apparatus by which the inductances of the secondariesof the transformers or couplers are varied in steps by means of a singlecontrol arrangement.

Another feature of my invention has to do with the manner in which theinductance within the steps is varied by means of a separate singlecontrol unit.

Another feature of my invention has to do with the manner in which thecontact or wiper arms for varying the inductance of the transformers bysteps are associated with the control arrangement.

A still further feature of my invention is the manner in which therotary supports within the stator supports are held in position, and thenovel means which are provided for leading the terminal ends of rotarycoils to terminals which are adapted to receive connections from anexternal circuit.

A further feature of my invention is the novel shielding means which areprovided for shielding the transformers and the means for securing thesame in position.

A still further feature of my invention is the provision of a novelwiper arrangement in association with a conducting element to providemeans for connecting the wiper with an external circuit.

The above features as well as others not specifically pointed out willbe more fully described and explained in the following specification andfor a more complete under- Serial No. 220,333.

standing of my invention reference may be had to the accompanyingdrawings in which like references in the several views denote like partsand in which:

Fig. 1 is a top view of the apparatus comprising my invention inassociation with a mounting panel and mounting base.

Fig. 2 is a front view of Fig. 1 with the mounting panel removed and thefront of the shielding members cut away.

Fig. 3 is a sectional view along the line 33 of Fig. 1 which clearlyillustrates the means for controlling the rotor elements of thetransformers.

Fig. 4 is a sectional view along the line 44 of Fig. 1 which clearlyillustrates the means that controls the wipers which engage contactsassociated with the tapped secondaries of the transformers.

Fig. 5 is a sectional view through one of the transformers to illustratethe means for carrying the terminals of the rotor winding to externalterminals.

Fig. 6 is a sectional view along the line 66 of Fig. 1.

Fig. 7 is a fragmentary View of the wiper and arm of a switch unitillustrating their association with the shaft to which they are secured.

Referring now particularly to Fig. 1 the devices or transformers T, T, TT are each provided with a cylindrical frame or stator tube 2, 8, 4 and5 respectively and mounted within the stator tubes are rotatablecylindrical frames or rotor tubes 6, 7 8 and 9 shown in dotted lines inFig. 1. The stator coils, 2, 3, a and 5 are mounted upon a base board 10by brackets and as each of the stator coils is mounted in a similarmanner a description of one will suffice. A U-shaped bracket 11 isprovided with diverging legs 12 and 13 which are provided with tappedorifices 1 1, and screws 15 which pass through suitable orifices in thestator tube 2 near its peripheral edge have threaded engagement with thetapped orifices 14 in the respective legs 12 and 13 of the bracket 11 tosecure the stator tube 2 to the bracket 11, the brackets 11 being inturn secured to the base board 10 by means of screws 11. I

The rotor tubes 6, 7, 8 and 9 are supported on a. rod 16 of suitableinsulation material such as bakelite and as the rotor elements aresupported on the rod 16 in a similar manner a detailed description ofone will suffice, The rotor element or tube G is provided with a pair oforifices 17 and 18 diametrically opposite which are adapted toreceive'fthe sleeve extensions 19 of a pair of -bushings: 20"" securedwinner circumferential face 'of' 'the tube 6 by means of rivets 21. Thestator tube 2 is provided with a pair of orifices-22 and 23diametrically opposite and in alignment with" o'rifices 241 5 whichextend through the" sleeve extensions 19 of the bushings 20'." Theorifices 22 and 2 3 in the stator tube 2 and the orifices 2 1 in thebushings 20.3are of the same size and arein alignment, and they. areadapted to receive sleeves 25 and 26-- whicl1- are of a size to receivethe supporting rod '16. u

The bushings ltlfof the rotor tube 6 are provided'with tapped orifices28 which are adapted to receive screws 29the-ends of whi-ch pass throughorifices 30 in the sleeves 25"and 26 'to permit the same to" cngage therod 16 torigidly secure the rotorftube are the rod' 18';- The sleeveextensions lil'jof the bushings- 20: protrude through the diametricallyopposite orifices 17 and'18 an equal distance a thatthe distance betweenthe respective ends ofthe'sleeve extensions 19' is approximately thatofjthe innerdiameterof the stator tube 2,'so"that the ends of thesesleeve extensions 19' when the rotor 6'is plositioii ed'in the=statorvttube 2 on the rod 16 engage the inner circuml z, '4 lin .7 ferentialface of the stator tube 2 and prevent lon itudinal movement of "therotor".'tube -b v on'th'e supporting rod'16." The rod 16ipa'sses r l 7throughtherespective sleeves 25 and 26 assoclatechwith each 'of theother rotor tubes. 7,; 8 and 9, and these rotor tubes 7, 8and"9 securedtotthe rod 16'byse't'screws 29 asdescrlbed-in connectlonw th rotor tubeSand astherod 161s rotated the rotor behest; 7;

.8. and 9 which are secured thereto by th'e'set screwsaa, aresimultaneously" rotated. VThe transformers T", T, and To 'arejof thedegree coupler t pe; so that the rotor'tubes 6', 7, 8 and 9niayb'e'r'otated 90' degrees or'un til they are right angles to theaxis" of a the tweenjthe transformers T and T and is pro;

vided with an integrally formed portion- 36 extending upward at rightangles from the bracket 31 and is provided wvith' an orifice throughwhich the 7 rod '16-, which supports therotortubes 6,7, 8 and 9;extends: ,rhsl'lit'ft 37 rotatably supportedinintegrally;formed Theother end-' 3P ofth'e shaft 37 extends through an orifice in thepanel-32 'and has secured to its protruding end a graduated dial--Dadapted to rotate the shaft 37 and through the medium of the gears 10and ll andfi-dd 16 the rotor'tubes 6; 7 8an d' 9 are rotated'simultaneously. The dial D is provided with suitable'graduations" and asuitable" mark is pla ced' upon the front of thepanel 32 to indicate thedegree of rotation-1 of the rotor elements. A stop in 13 secured to vthe shaft- 37 and angular extensions 44: on; the bracket, 31 cooperateto prevent excessiverotationof the shaft 37. A'coil spring- 45 rsplaced" around ithe shaft'3'Z with one end resting aga nst the extendedportion 39 A of the bracket 31- and. its other end resting againstecollar flfi adapted to, be rigidly secured to the shaft'37 by means of asetscrew e'i- The coll-arefi-maybe' slid longi tudinally along theshaft;37" topermit the tensionor compression of thecoil spring 45- t6 beuste'd'and this spring 45' causes the bevel gear lOjon; the-shaft 37 tobe held in meslrwith the bevel ge'artl on the rod 16 to prevent --any'lost motion between the rod 16 and the shaft 37 and to alsoprovide=frictionalmeansto maintain; the rotor elements in-anyadjustedpositioni- The stator coils-SC, SC; SC a-nd S' C are tapped and theseta'ps-are-led to contacts 18 mounted on panels49 50,-51 and 52, and asall of -the panels are'fof similar construction and-arrangement'thedescription of one will sutfi'c-efor a clear explanation of all: Thepanel 19 associated-with the stator-coil SC is rectangular iii-shape andof suitable insulating material such as bakeliteand is providedwithsuitable orifices 53 equally;

spaced-apart which are adapted to receive contacts-8-.- The contacts 48are provided with reduced portions 48 which extend-i throughthe-orifices 53to which the taps or L leads 5 1 from the tapped statorcoil SC are fastenedby: suitable means such as solder.

. The-contacts 18"are=secured in the. orifices 53 1 11-11116 panel- 19in i any; suitable manner and are arranged-in anarcota-cIrcle, and" aw'viper arm- 55=-is" adapted to passover and engage the-contacts48r The'wiper'arms55, v

56," 57'a1rc l58' are-multiple controlledand adaptedto bemovedcorresponding distances? simultaneously, so that the" inductances'ofthetransformers} T, T T d/r3 be varied byplacing,a' diiferen-t number ofturns of 1 wire F composing thesecondaries" of? thetransformersincircuit. By}u'singamultiple control device the same numberof turns will be used on each coil, and thus the most eflicient resultswith the simplest operation will be obtained and the means foraccomplishing this will now be described.

The panel 49 associated with the transformer T is located forward of thesame and is secured to the integrally formed angular extensions 59 and60 of the U-shaped bracket 11, which supports the stator tube 2, bymeans of screws which pass through openings in the panel and havethreaded engagement with tapped orifices in the extensions 59 and 60.Additional securing means for the panel 49 in the form of a bracket 61is secured to the same by means of a rivet 62 and is provided with anintegrally formed pin member 63 which extends through an orifice 64 inthe stator tube 2 to rigidly secure the upper portion of the panel 49against movement A bushing 65 provided with a reduced portion 66 isinserted into a suitable orifice 67 in the panel 49 and the reducedportion 66 in the orifice 67 extends slightly beyond the face of thepanel 49 and is upset or spun over to secure the bushing 65 to thepanel. The bushing 65 is provided with a central orifice 68 which isadapted to receive a stub shaft 69 which extends through this orifice68, and the protruding end 69 of the shaft 69 has a portion cut away toform flat face 70. A bushing 72 is provided with a circular orifice 73in its one end and with an orifice 74 in its other end shaped toconform, with the formed end 69 of the shaft 69 which extends into thisshaped orifice 74. The end 69 of the shaft 69 protrudes slightly intothe circular orifice 73 of the bushing 7 2 and this protruding end isstaked over to secure this bushing 7 2 to the shaft end 69.

A shaft extends through an orifice 81 in the front panel 32 into theorifice 73 in the bushing 72, and a screw 82 having threaded engagementwith a suitable tapped orifice in the bushing 72 engages this shaft 80to rigidly secure the same in the bushing 72. The wiper is provided witha dished portion 55 having an orifice 71 of a size and shape to fit overthe formed end 69 of the shaft 69 and this dished portion 55 of thewiper 55 when positioned on the stud shaft 69 rests between the bushing65 in the panel 49 and the face of an arm 7 6 secured to the bushing 72.It is readily apparent that as the shaft 80 is turned through the mediumof a knob K secured to the end protruding through the panel 32 thebushing 72 and the stub shaft 69 secured to the bushing 72 and the wiper55 which is supported on the stub shaft 69 are rotated as a wholecausing the free end 52 of the wiper to engage successive contacts 48,as it is rotated from ieft to right and vice versa, through the mediumof the shaft 80. The arm '76 secured to the bushing 7 2 is also rotatedand this movement of the arm 76 is for purposes as will presently bedescribed. A bracket 85 secured to the panel 49 by the screws 7 5 isprovided with an upwardly extended portion provided with an orifice 86through which the shaft 80 extends and serves as a bearing when the sameis rotated and the bushing secured to the panel 49 and through which thestub shaft 69 extends serves as a bearing for the shaft 69 when it isrotated through the agency of the shaft 80 as just described. To preventany overrun of the free end 55 of the wiper 55 as it passes from onecontact 48 to the next and also produce a snap action as the wiper 55passes from contact 4.8 to the next, the arm 7 6 is provided with adownwardly extending portion F6 provided with a piurality of notches 86in its arcuate shaped edge equal in number to the contacts 48 secured tothe panel 49.

The bracket secured to the plate 49 as already described is providedwith an orifice "Z which is adapted to receive a ball bearing 88. A leafspr'ng 89 secured at its one end to the bottom t r: of the bracket 85has its free end engagi the ball bearing 88 which rests in the orifice87 to maintain the ball bear-i 88 in engagement with the The ballbearing notches 86 ill the arm 76. 88 cooperates with the notches in theextended portion 76 of the arm 76 and as the shaft 80 is rotated the arm76 also rotates causin a tooth formed by two adjacent notches 86 toengage the ball bearing 88 force it down against the normal tension thespring 89 and as the arm continues its rotation the ball 88 p the tooth90 and. acts upon the nextnotch 8 underthe influence of the spring 89 soas to give a quick snap action to the wiper 55 and arm 76 as the wiper55 passes from one contact to the next. The wipers 56, 57 and 58associated with T and T are rotatably and the transformers it supportedin a manner similar to that described in connection with the 'iper 55 ofthe transformer T and a description of one will suflice to give a clearunderstanding of all. The bushing 91 secured to the panel by staking itsprotruding end and is provided with a central or which receives a stubshaft 93. The stub shaft 93 provided with a flat portion 94 and thewiper 56 and arm 77 are provided with orifices shaped to permit thembeing slipped on the end 93 of the stub shaft 93 and the end of the stubshaft 93 protruding siightly beyond the face of the arm 7. is stakedover to secure the wiper 56 and arm 7'? to the stub shaft 93. The wipers57 and 58 and arms Y8 and 79 associated with the transformers T and Tare secured. to stub shafts and 96 in a similar manner and the wipers55, 56, and 58 and arms F6, 77, 7S and 79 are rotated simiiiitaneouslythrough means to he presently described.

A link 100 provided with a bifurcated end 101 is associated with thefree ends of-each of the arms 76, 77, 7 8 and 79 and straddle the sameand are pivotally secured thereto by means of pivot pins 102. Each linklOO is provided with an orifice 108 which are adapted to receive a rod104. Set screws 165 having threaded engagement with suitable tappedorifices in the ends of the links 100 engage the rod 104 to rigidlysecure the rod 104; to the links 100 to connect the rod 10 1 with thearms 76, 77, 7 8 and 79 associated with the wipers 55, 56, 57 and 58. Itis readily apparent that when the shaft 80 is rotated through the agencyof the knob K secured to the same, the arm 76 secures to the bushing 72to which the shaft 80 is secured is rotated, and through the agency ofthe links 100 which connect the arms 76,77, 78 and 79 to the conneotingrod 10 1 the movement of 1711-9111311 76 is transmitted to the arms 77,78 and 7 9 to simultaneously move them.

The arms 76, 77 78 and 79 are provided with depending legs 106 which areso spaced apart so as tospa-n the wipers 55, 5.6, 57, and 58. The arm 76 is associated with the stub shaft 69 as before described and as thearms 77, 7 8 and 79 are secured to the stub shafts 93, 95 and 96 asbefore described the movement of the arms causes rotation of the stubshafts 93, 95 and 96. I The wiper-s55, 56', 57 and 58 are secured tothe. stub shafts and as thestub shafts are rotated by the arms securedthereto the wipers 55, 56, 57 and 58 also move to cause the free ends ofthe wipers to move from one Contact to the next. A pair of stop pins 110secured to each of the panels l9, 50, 51 and 52 are provided to limitthe movement of the wipers from left to right and vice versa, thesestops110 of course being engaged by the respective edges of the arms 76,77, 78 and 79. 1

"lern'iinals 111 secured to the stator tubes 2, 3, 1 and 5 pr videmeansfor securing the terminals o'l'the windings 0 the stator coils C andalso provide means for connecting; the external conductors of anelectrical circuit. A pair of terminals 112, 112 secured to the statortubes 2, 3, 45 and 5 by means 01'' screws 1.13 and nuts 114 are providedwith integrally formed parallel spring arms 11-5 the free ends of whichrespectively sleeves 25 and 26 which extend intothe bushings whichsupport rotor tubes 6, 7,8 and 9 on the rod 16. The bushings 20 areprovided with integrally formed terminals 116 to which the terminalwindings of the rotor coil RC are secured. The bushings 20 and sleevesand 26 which extend into the bushings 20 are made of suitable conductingmaterial and contact each other so that the winding terminals of therotor coil RC are provided with a conducting path including therespectivebushings 20 and sleeves 25 and 26 and'the arms 115, of therespective terminals 112 secured to; the stator tub-es. Enternalconduc-l tors may be secured to the terminals112 and thus connecttheterminalwindings of the rotor. coils RC i to an external circuit.

he wipers areiprovided tvithintegrally formed dished semicircularportions 56 57 ai1dfi58 -and are split into sections 120 which -areebentdown to-engage. disks 121 whichare providedwith orifices of a size tofit on the'reduced portions of the bushings :secured to the panels 119,50, 51 :andv52. The disks 121 are provided with extended portions122=Wl1=i0l1itf6 secured to the panelsiby means of suitable screws andare so formed that when the disks 121care positioned on the bushing-sbetween the::"iace oft-he panels a-nd'the bent sections 1 0 the Wipersthe same are placed under-tension to firmly engage these portions 120 ofthe :wipersto providerubbin contacts between thedisks 55, 56 ,57 58 andthe wipers. The extendedportions 122 of the disks .121:are associatedwith terminals l -iht-G which ex ternal conductors. are connected andthrough the agency of the extensions 122 and the-disks 1'21 whichiareincontactual engagement with the wiper disks current isthus carried to thewipers. Y r

'l helrespective transformers T, T, T and T are shielded and for thispurpose 1 provide containers or shields C, (EC C :and C constructed ofsuitable metal such as copper and as eachone is a similar construction adescription of one will suiiice. The container C comprisesra base 125secured to-the sub panel ;10'by means of screwsll which also secure thebrackets 11 to the baseboard 10. A suitable strip of insulation 126isplaced between thebracke't 11 and the base 125 to insulate thebracl'zet'11 from the base 125. The base 125 is provioed with upturned'edges 126land a square shaped tube or shell 12". is

adapted to surround the transformer T and rests on the base 125 insideof the upturned edges 126 of the same. The opposite walls 128 and 129 ofthe shell 127 are provided with alignedv oblong slots 130 through whichthe rod 16 which supports the rotor elements R, It, R and 11 extendsAligned oblong orifices 131 in the opposite walls 128-andi129 permit thepassage of the rodlOs which connects the arms 76, 77, 7 8 and 79together. A cover 132 with depending edges 133 sets on the shell 127,and with the shell 127 and base 125 as a whole form a container orshield'C for the transformer T. A rod 1341 secured to sub panel 10 bymeans of nuts 135' extends upward between the containers C and C and aspring clamping member 136 provided with an orifice through which therod 134 extends engages the covers 132 of the respective containers orshields C and C. A nut 137:hav ing threaded engagement with the end ofthe rod 13 l' is turned down against the clamping member 136 to placethe sameundertension to hold the cover andshell in'position againstmovement. The shield C in addition is provided with a slot 140 throughwhich the bracket 85 and shaft 80 extend. The con tainers or shields C,C and C are of similar construction and the containers C and C are alsomaintained in position by means of a rod i l-1 and clamping member 142.The shields (J, C. C and C shield the transformers T, 'l", T and T as iswell understood.

The knob K is rotated to change the inductance of the windings incomparatively coarse steps while the dial D operates to vary theinductance of the secondaries within the steps of inductance between thetaps.

The bevel gears which connect the shaft 16 to the shaft 44 have a 2 to 1ratio so that the dial D moves 180 degrees for a 90 degree movement ofthe rotor elements. By this method a fine adjustment of the rotorelements may be made for a coarser adjustment of the dial D.

vVhile I have described a preferred embodiment of my invention I do nothowever wish to be limited to the exact structure as shown but aim tocover all that comes within the spirit and scope of the appended claims.

Having described my invention what I claim is new and desire to secureby Letters Patent of the United States is:

1. A device of the character described including a wiper and an armsupported on a rotatable shaft, said arm having a pin secured thereto, amounting panel having a plurality of contact points secured thereto,said wiper having an orifice adapted to receive said pin secured to saidarm and being adapted to engage said contacts, a split end portion forsaid wiper, a member associated with said wiper having one end securedto said panel and its other end under tension to contact with saidportion of said wiper, means integrally formed with said arm andcooperating with spring pressed means for maintaining the said wiper inengagement with any selected contact.

2. A device of the character described including a mounting panel and aplurality of contacts supported thereon, a wiper and an arm supported ona rotatable shaft on said panel, means secured to said arm and engagingsaid wiper to assure the rotation of said wiper, said wiper adapted toengage said con tacts, a split end for said wiper, a conducting memberassociated with said wiper having one end secured to said panel and itsother end under tension engaging said split portion of said wiper, anarcuate shaped member integrally formed with said arm, a bracket securedto said panel and spring pressed means in said bracket cooperating withnotches in said arcuate shaped member to maintain said wiper inengagement with any selected contact.

3. A device of the character described including a mounting panel and aplurality of contacts supported thereon, a wiper and an arm supported ona rotatable shaft, means secured to said arm and engaging said wiper toassure the rotation of said wiper, a dished end for said wiper, acurrent conducting member associated with said wiper having one endsecured to said panel and its other end under tension engaging saiddished split portion of said wiper for contact purposes, an arcuateshaped depending member for said arm, a bracket secured to said panel, aball member resting in an orifice in said oracket, notches in thedepending member of said arm, and spring means for pressing said ballmember in said notches to maintain said wiper in engagement withselected contacts.

4. A device of the character described including a plurality of mountingpanels each having a plurality of contacts, a. wiper and an arm for eachpanel and a shaft supported by each panel to which said wipers and armsare secured, means secured to said arm and engaging said wiper to assurethe rotation of said wiper, pivoted. links secured to said arms, acontrol member associated with the shaft of one of said wipers and arms,means extending through said links and secured thereto to cause movementof all of said arms to cause movement of said wipers to engage saidcontacts when said control member is rotated, and means associated withsaid one of said arms to maintain said wipers in engagement withselected contact points.

5. A device of the character described ineluding a plurality of mountingpanels, each having a plurality of contacts, a wiper and an arm for eachpanel and a shaft supported by each panel to which said wipers and armsare secured, means secured to said arm and engaging said wiper to assurethe rotation of said wiper, pivoted links secured to said arms, meansextending through aligned orifices in said links and secured thereto tolink said arms together, and a control member associated with one ofsaid arms to cause movement of said one arm which through the agency ofsaid means secured to said links causes the simultaneous movement ofsaid arms and wipers, said wipers engaging successive contacts on saidpanels.

6. A device of the character described including a plurality of mountingpanels each having a plurality of contacts, a wiper and an arm for eachpanel, a shaft supported by each panel to which said wipers and arms aresecured, means secured to said arm and engaging said wiper to assure therotation of said wiper, connecting links secured to said arms, alignedorifices in said connecting links adapted to receive a connecting rod,means for securing said rod to said links, a control shaft connected toa shaft of one of said wipers and arms to cause the movement of said armand wiper which causes the simultaneous operation of said arms andwipers by means of said link and connecting rod to cause said wipers tosimultaneously engage corresponding contacts in each set of contacts onsaid panels.

7. A device ofthe character described including a plurality of contactplates, wipers rotatably supported by said contact plates, Wiper,control members, control devices pivotally secured to said. wipercontrol. members, a control shaft associated with one ofsaidwiper 1control members, and a rod extending through said control devices foreffecting operation. of, said contact wipers when said control shaft isrotated, and metal housing members-enclosing said contact platesprovided with orifices through which said rod extends.

8. A device of the character described includinga plurality of contactplates, wipers rotatably supported by SiLlCla contact plates, wipervcontrol members, control devices pivotally secured to said wiper controlmembers, i a control shaft associated with one of said 5 Wipercontrolmembers, and a rod extending 0 through said control devices foreffecting, operation of said contact wipers when said control shaft isrotated, and metal housing members enclosing said contact platesprovided with orifices through which said rod extends, and yieldingmeans for holding covers on'said metal housing members.

Signed bvme at Chicago, in the county of Cook and State ofIllinois',this 31stday. of August, A. D. 1927.

ERNEST A; BOHLMANi

